1. Field
The present invention generally relates to tow vehicles and drawn trailers and, more particularly, to removable visual devices used to assist a tow vehicle operator to align the vehicle's tow hitch assembly to the trailer's hitch receiver assembly, in most cases a tow ball and trailer hitch respectively, however embodiments can be fashioned to work with pintle hitches or other tow vehicle to trailer hitching mechanisms.
2. Description of Related Art
There are many methods and apparatuses devised to assist a vehicle operator when reversing a vehicle to align the vehicle's ball to a trailer hitch assembly for the purpose of coupling. Prior devices have been either costly, complex, time consuming for assembly or disassembly, or for single purpose, and most rely on an unobstructed view from the interior of the tow vehicle's rear view mirror.
Relying on the rear view mirror of the operator's vehicle seriously limits the effectiveness of such devices, since a direct line of sight from the mirror through the back window to the alignment indicators of these devices can be compromised by the presence of people or goods in the back seat, or obstacles within or at the back of the truck bed, or by vehicles that have no such rear window at all. This compromised line of sight prevents such devices from working effectively or even at all.
Such shortcomings can be seen in CA23007405 (THORNTON) (related to U.S. Pat. No. 6,076,847), U.S. Pat. No. 6,612,603 (ALGER), U.S. Pat. No. 6,557,483 (NATHAN), U.S. Pat. No. 6,712,378 (AUSTIN), U.S. Pat. No. 6,764,091 (GRASSO), U.S. Pat. No. 6,454,290 (TURNER), U.S. Pat. No. 6,422,582 (GLASS), U.S. Pat. No. 6,357,126 (GILLEN, Jr.), U.S. Pat. No. 6,279,940 (BEAVINGTON), U.S. Pat. No. 6,102,423 (BECK), U.S. Pat. No. 6,022,116 (OSBORN), U.S. Pat. No. 5,979,927 (HALE), U.S. Pat. No. 5,971,555 (WILCOX), U.S. Pat. No. 5,680,706 (TALCOTT), U.S. Pat. No. 5,669,621 (LOCKWOOD), U.S. Pat. No. 5,558,352 (MILLS), U.S. Pat. No. 5,482,310 (STAGGS), U.S. Pat. No. 5,478,101 (ROBERSON), U.S. Pat. No. 5,309,289 (JOHNSON), U.S. Pat. No. 5,036,593 (COLLIER), U.S. Pat. No. 5,035,441 (MURRAY), U.S. Pat. No. 4,856,200 (EMERICK), and U.S. Pat. No. 4,285,138 (BERRY).
A solution that utilizes the side view mirrors, so that vision of alignment indicators cannot be compromised by objects in the vehicle, or for a lack of a sightline through the vehicle to the indicators, would be a more effective method. In addition, the built-in redundancy in having two, rather than one line of sight for alignment can be seen as a positive improvement on the performance of the task.
CA2100375 (KNISLEY) (related to U.S. Pat. No. 5,338,047) describes a direction-orientable wheeled-body device having a socket to receive the lower end of a trailer's vertical tongue jack, configured such that movement of the wheel aligns the trailer's hitch socket with the hitch ball of a towing vehicle. Wheel movement is achieved by rotation of a gear in engagement with the wheel. Unfortunately, this device would require physical exertion by the user to move the trailer into alignment with the tow vehicle, such exertion varying with grade and load of the trailer. This process could possibly be a detriment to a person with little physical ability.
U.S. Pat. No. 5,224,270 (BURRUS) describes a removable alignment device using an operator's side mirror to align crosshair elements of the tow vehicle to the trailer. The device lacks consistent positioning between elements on the vehicle to elements on the trailer for accurate setup, lacks an identifier for a stop point while reversing toward a target at the point where the ball and hitch meet for coupling, and lacks means for accurate alignment as the crosshair element mounted to the rear view mirror prevents the user from having the accurate depth perception required to anticipate where the ball of the vehicle would meet the hitch of the trailer, especially at angles of attack wherein the general axes of the vehicle and trailer are not in line with each other. A better solution would be to allow the operator to see markers for both the ball and hitch at their respective distance as seen through the rear view mirror for accurate depth perception and corresponding ability of the operator to anticipate the proper stop point.
U.S. Pat. No. 5,115,572 (HARBISON) describes an adjustable alignment device using cross members supported by the ground that are adjustable for alignment purposes. Alignment is achieved when the driver's side rear wheel is channeled along a forward member, and touches a cross member of the device. This device would require time-consuming adjustment for different types of vehicles and wheel sizes and does not show a definite stop point because of the difficulty to judge when the distal end of the rear tire touches a cross member while reversing without colliding the cross member or forward member that could cause damage to either the vehicle, its tires, or the invention. The product is cumbersome and complicated, is vulnerable to human error as there are no fixed references to either the tow ball or hitch, and can be knocked out of place or alignment or knocked down by the vehicle. There are no visual clues for the stop point, only the feeling the driver may experience when the rear tire or tires of the vehicle impacts the forward cross member of the invention.
U.S. Pat. No. 5,113,588 (WALSTON) describes an alignment device that may be used with the interior rear view mirror or a single side mirror. The invention uses two sighting elements fastened by magnets to respectively the rear of the towing vehicle and tongue of the towed vehicle, upon which are mounted rings that when brought together form a toroid to indicate alignment; the differences of height between the rear of the towing vehicle and the towed vehicle tongue would require height adjustment susceptible to human error between male and female sighting elements as while setting up the operator must align the two elements at a specific height based on the operator's prediction as to where the elements will meet in a manner that they are substantially overlaid when the towing vehicle and the towed vehicle are brought together.
Positions that must be viewed from the rear view mirror can be compromised by obstacles in the rear view mirror or by vehicles with no rear view mirror at all. In positions where the sighting elements are positioned to any degree horizontally the accuracy of the length adjustment is particularly subject to human error as the device must be extended beyond the width of the vehicle, and as such must be retractable from a closed position if stored in the trunk of a vehicle, and the extensible arms of both the vehicle and trailer extension rods must be supported by a single pivoting socket point without other means of support or counterweight to ensure that the targets are in proper and anticipated position despite the influence of gravity causing the ends to sag or causing the entire device from torquing from a moment at the pivoting socket.
This method of alignment doesn't take into consideration the unevenness of the terrain which may make aligning the sighting elements difficult. Nor does it provide an accurate guide to bring the operator to the point that the elements are substantially overlaid, especially when viewed through the side view mirrors where the elements are relatively at an angle from a vertical center line of the vehicle as seen from the rear view mirror where the operator is approaching the sighting element on the trailer from angle of attack wherein a plane aligned with a centerline drawn through the vehicle perpendicular to the ground is not coincident to a plane aligned with a centerline drawn through the trailer perpendicular to the ground, because approaching the sighting element on the trailer with the sighting on the vehicle does not ensure that the ball and hitch are following a parallel path to the path between the sighting elements and the direction of the vehicle so guiding them together so that the ball and hitch meet at a stop point where they can be joined. The ultimate goal is to join the ball and hitch, not bring the sighting elements together, which this invention does not achieve accurately. Another downside is the magnetic fastening means for this unit since there are many new composite and plastic materials in styles of bumpers on present or future vehicles which will not adhere to a magnet.
U.S. Pat. No. 4,687,220 (DANIELSON) describes a detachable signaling device with telescoping members that signals when it contacts a trailer, whose intention it is to visually indicate the alignment of the hitch elements; however, the device projects longitudinally and only functions properly when the longitudinal axes of the tow vehicle and trailer are perfectly lined up, and only then provides a signal that the hitch elements are at the proper distance to one another longitudinally and makes no reference to lateral alignment to center the tow vehicle to the trailer so that the hitch elements actually meet.
A complicated system of suction cups and brackets are available to fasten the system to the tow vehicle in order to allow the device to be positioned in a manner so as to hit the trailer on a surface when reversing, but doesn't account for potential unavailability of tow vehicle surfaces to mount to that will allow the device to touch a trailer, such as a trailer that is lower and narrower than mountable surfaces of the tow vehicle. The suction cups are seen as inferior mounting means as the likely presence of dirt, silt, water, rain, snow, ice, frost, paint irregularities, rust, dents, or irregularities in the form of the car surface will cause the suction cups to fail.
The tail end of the invention intended to touch an impact strip on the trailer moves toward the trailer like a lance and could pierce the impact strip if the driver reverses too quickly, damaging either the invention or the trailer, and likely knocking the invention off of its suction cup mounts. Different styles of trailers would consistently create new adjustment points to the operator. Given a situation where the invention was not previously calibrated to a trailer already hitched to a tow vehicle, assembly and accuracy of the device would be highly prone to human error.
U.S. Pat. No. 5,951,035 (PHILLIPS, Jr.) describes an alignment system using a photoelectric sensor and alerting device. This device shows modification to the ball assembly which may be costly and take away from the integrity and strength of the ball unit of the tow vehicle. The device shows no other means for alignment except when the ball unit is already aligned to the hitch assembly of the trailer and therefore does not function as a guide to bring the two vehicles to this alignment. The device is intended only for ball and socket type hitch assemblies.
U.S. Pat. No. 6,480,104 (WALL) describes the use of a number of ultrasonic transducers being transmitted to a control unit. This device is time consuming and complicated to set up, limits use, requires proper surfaces for mounting, and the transducers could be subject to damage from the environment, road debris, or accident, or to loss or theft if left mounted.
Wireless transducers, as in the preferred embodiment, require a power source that might not always be available, as in the case of failed batteries, and as such batteries are disposable will create waste hazardous to the environment. When the power source is derived from a hook-up, the user must remember to do so, make the effort to do so, and deal with cumbersome lengths of wire that the user will have to remember where they were stored, or that could be damaged if left in place, such as on the rear of the vehicle. Wires that access the transducers in a concealed manner generally must pass through user drilled holes in the car body, potentially damaging the integrity of the car body.
Learning to use the device and making a mental picture of the events appearing on the display of the handheld device and correlating them to events and movement of the vehicle happening in real time in the real world behind the user may be difficult for users, compared to actually seeing visual references of alignment on the vehicle and trailer themselves. Relying on the display and not visual references through the rear view mirrors could lead to an accident when reversing.
U.S. Pat. No. 5,274,432 (PARENT) describes an alignment monitoring system using side markers on the vehicle and trailer for observing alignment of a towed vehicle while traveling where the driver cannot see the towed vehicle through the side view mirrors. The markers are fixed to the vehicle and trailer for observation in transit only, and are not intended to facilitate aligning a vehicle and trailer for purposes of coupling the ball and hitch of those vehicles respectively. The device has lights and reflective surfaces to allow it to be seen at night, but these function as visual references and not signals that turn on and off to show whether the coupling elements are at a stop point. This device does not have any indicator of when the tow vehicle ball is aligned to the trailer hitch socket at a stop point as this is not the intention of the invention.
Accordingly, a better solution not encumbered by the foregoing limitations would be desirable.